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Full-Text Articles in Engineering
On The Design Of Coreless Permanent Magnet Machines For Electric Aircraft Propulsion, Damien Lawhorn, Peng Han, Donovin Lewis, Yaser Chulaee, Dan M. Ionel
On The Design Of Coreless Permanent Magnet Machines For Electric Aircraft Propulsion, Damien Lawhorn, Peng Han, Donovin Lewis, Yaser Chulaee, Dan M. Ionel
Power and Energy Institute of Kentucky Faculty Publications
This paper presents design and prototyping studies for coreless and slotless permanent magnet (PM) machines, which have the potential for high power density and efficiency, and discusses their feasibility for electric aircraft propulsion. The emphasis is on axial flux permanent magnet (AFPM) machines with printed circuit board (PCB) stators that have advantages over their wired counterparts in terms of design flexibility, coil accuracy, manufacturing process reliability, and heat dissipation. Detailed electromagnetic finite element analysis models were developed and employed alongside analytical sizing equations to evaluate the performance of two dual-rotor single-stator coreless AFPM designs employing wave and spiral PCB winding …
Evaluation Of Bearing Voltage Reduction In Electric Machines By Using Insulated Shaft And Bearings, Peng Han, Greg Heins, Dean Patterson, Mark Theile, Dan M. Ionel
Evaluation Of Bearing Voltage Reduction In Electric Machines By Using Insulated Shaft And Bearings, Peng Han, Greg Heins, Dean Patterson, Mark Theile, Dan M. Ionel
Power and Energy Institute of Kentucky Faculty Publications
Bearing voltages and corresponding currents in electric machines driven by pulse width modulation (PWM) converters with fast switching and high dv/dt can cause premature bearing failures. This paper evaluates the bearing voltage reduction by using insulated shafts and bearings. An equivalent circuit representation of electric machines taking into account high-frequency effects is developed to show the production mechanism of bearing voltage, based on which simulations are performed with detailed finite element models for transient and simplified equivalent circuit for steady-state analysis. The steady-state equivalent circuit is then calibrated, by combined numerical calculations and experimental measurements, and used to predict the …
Electric Drives With Wide Bandgap Devices For Two-Phase Very Low Inductance Machines, Yibin Zhang, Damien Lawhorn, Peng Han, Aaron M. Cramer, Dan M. Ionel
Electric Drives With Wide Bandgap Devices For Two-Phase Very Low Inductance Machines, Yibin Zhang, Damien Lawhorn, Peng Han, Aaron M. Cramer, Dan M. Ionel
Power and Energy Institute of Kentucky Faculty Publications
Slotless and coreless machines with low inductance and low core losses are attractive for high speed and high power density applications. With the increase in fundamental frequency, typical drive implementations using conventional silicon-based devices are performance limited and also produce large current and torque ripples. This paper presents a systematic study of proposed drive configurations implemented with wide bandgap (WBG) devices in order to mitigate such issues for 2-phase very low inductance machines. Two inverter topologies, i.e., a dual H-bridge inverter with maximum redundancy and survivability and a 3-leg inverter for reduced cost, are considered. Feasible modulation schemes are derived …
A Comparative Study Of Constant Power Operation Techniques For Low Inductance Machines, Damien Lawhorn, Narges Taran, Vandana Rallabandi, Dan M. Ionel
A Comparative Study Of Constant Power Operation Techniques For Low Inductance Machines, Damien Lawhorn, Narges Taran, Vandana Rallabandi, Dan M. Ionel
Power and Energy Institute of Kentucky Faculty Publications
In traditional electric machines, it is usually possible to achieve constant power high-speed operation by employing field weakening through the injection of a negative d-axis current component. However, in machines with low armature inductance, such as high power density permanent magnet synchronous machines, and more specifically, coreless machines, which are gaining increasing attention because of their high specific torque, the extended speed range obtained using this method is very narrow. This paper summarizes the performance characteristics of existing approaches for obtaining constant power operation and proposes two new techniques, specially applicable to coreless axial flux permanent magnet machine namely, current …